1. Field of the Invention
The present invention relates to a radiant heating apparatus and method for heating an article to be treated or processed, and more particularly to a radiant heating apparatus and method which can heat uniformly a large article such as a semiconductor or quartz glass substrate having a large size or diameter in various kinds of processes in which the article is subjected to, for example, heat treatment, film growth by CVD or epitaxial growth, or a like process.
2. Description of the Related Art
Recently, associated with a considerable increase in the degree of integration of a semiconductor circuit, the area of one device chip has increased. As a result, the diameter of a semiconductor substrate which serves as a base material has become increasingly larger. In the case where devices are formed on such a semiconductor substrate, a heating apparatus or the like, which carries out various heat treatments for a quartz substrate used as a photomask or a semiconductor substrate, inevitably increases due to an increase in the size of the semiconductor substrate.
As a result of an increase in the size of the semiconductor substrate, the quartz substrate, or peripheral members such as a heating apparatus, a temperature distribution inevitably arises when an article to be treated is subjected to various kinds of heat treatments. This makes it difficult to uniformly heat the article to be treated.
For example, if an article such as a semiconductor substrate is uniformly heated, formation of a slip dislocation, variation in the thickness of a grown film, or various types of degradation of electrical characteristics may occur. As a result, the yield of device chips formed from one semiconductor substrate is considerably degraded.
For example, presently the dominant diameter of a semiconductor silicon substrate is in the course of shifting from 150 mm to 200 mm. The future shift of the diameter to 300 mm or more is regarded to be inevitable. In the thermal treatment of a substrate having such a large diameter, further deterioration of the temperature distribution within the plane of the substrate is expected. There is a demand for a heating apparatus and method capable of uniformly heating a semiconductor substrate, an article to be treated.